


love making: lesson one!

by senkuishigmi



Category: Dr. STONE (Anime), Dr. STONE (Manga)
Genre: Bottom Senku, Established Relationship, First Time, Loss of Virginity, M/M, Making Love, Modern AU, Porn with Feelings, it's not just porn though it's actually sweet, my kink is safe and consensual sex between loving partners, sometimes if you want porn written right you gotta do it yourself, there's barely any bottom senku content and that is a crime
Language: English
Status: Completed
Published: 2020-07-13
Updated: 2020-07-13
Packaged: 2021-03-05 03:20:29
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,643
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25237594
Author URL: https://archiveofourown.org/users/senkuishigmi/pseuds/senkuishigmi
Summary: gen finds some interesting searches in senku's browser history. he thinks he can answer all his questions, far better than the internet ever could. senku is a hands on learner, after all.
Relationships: Asagiri Gen/Ishigami Senkuu
Comments: 8
Kudos: 173





	love making: lesson one!

**Author's Note:**

> i got the idea for this fic from [this prompt generator](https://prompts.neocities.org/) !

Gen raised an eyebrow, confused and slightly startled by the search results that lit up the screen in front of him. Of course, when borrowing Senku's computer, finding multiple open tabs of research upon starting the machine was no surprise. It was a given, really. It was only after closer inspection that Gen began to question it, because the words in the search bar were not about outer space, or chemistry, or anything of the like.

_how to please your partner in bed_

_where is the male g-spot_

_what is foreplay_

_how to prep for anal sex_

Gen felt his face heat up as he read. He glanced over the top of the screen, eyes landing on Senku, who stood on the other side of the kitchen with his back turned, completely oblivious that his private research project was not quite so private any longer. Gen's lips curved into a sly little smile as he watched his boyfriend. The blonde reached into the cupboard above him and pulled out two mugs.

"How do you want your coffee?" Senku asked, looking over his shoulder, "Same as usual?"

Gen forced the smirk off his face, trying to keep a neutral expression. "Yes, please."

Senku turned his back again, and Gen returned his attention to the screen. It was no secret that Senku was a virgin, but just how innocent was he? Well, maybe _innocent_ wasn't the right word. Still, Gen found it oddly endearing. He might even go so far as to call it cute.

Senku crossed the small kitchen and took a seat across the table from Gen, handing him one of the mugs. "Did you find what you were looking for?" he asked, gesturing to the laptop.

"Ah, I got a bit distracted. I forgot what I was even going to look up," Gen shrugged his shoulders, "but Senku-chan, did you find what _you_ were looking for?"

Senku stared blankly for a moment. "Uh, yes? The coffee maker hasn't moved since the last time I was here."

Gen bit back a laugh. Senku wasn't stupid, he was quite literally the smartest person Gen knew, but _god_ , the boy could be dense. "That's not what I mean, silly."

"Then what? I have no idea what you're talking about." Senku looked less than amused as he took a sip of his coffee.

"I mean," Gen smiled sweetly, "did you figure out where the G-spot is?"

Senku choked on his coffee, coughing and sputtering for a bit before he managed to speak. "What?!"

"Well, when I opened your computer, I noticed you left a bunch of windows open--"

"Shit," Senku covered his face with his hands as realization hit him, "You weren't supposed to- No one was supposed to see that."

"You should probably get in the habit of closing everything if you're going to be lending out your laptop." Gen took a quick sip of his coffee, then swirled it around in the mug. "Oh, this is good! You always make it just sweet enough."

" _Gen_ ," Senku groaned. He moved his hands to rake his fingers through his hair, revealing his face, which was absolutely on fire. "I can explain, okay?"

"Please do. Really, Senku-chan, we haven't even _gone there_ yet. Are you expecting something from me?"

"No!" Senku exclaimed, crimson eyes so wide they looked like they would pop out of his head, "I- I'd never _expect_ anything!"

Gen chuckled, reaching across the table to grab Senku's hand. "Relax. I'm just teasing. I _am_ curious about those Google searches, though."

Senku sighed, slumping in his seat, but not letting go of Gen's hand. "Don't laugh at me," he started, taking a deep breath, "I... don't know about you, but I feel like our relationship is getting pretty serious."

Gen nodded in agreement.

"I just... want to be prepared, if, or when, we get there. I don't have any experience, and I guess I'm afraid I won't be good enough for you."

"You don't ever have to worry about not being good enough," Gen said softly, running his thumb over Senku's knuckles. "I don't expect perfection. I just want _you_ , Senku." He guided the younger boy's hand to his lips, softly kissing his knuckles, then the back of his hand, then his wrist. "And you know, if you want to learn about those things, you don't have to go to the internet. I can just teach you hands on."

"Huh?!"

"You heard me, darling." He stood and swiftly made his way around the table, stopping directly in front of Senku. Before the blonde could say a word, Gen cupped his cheek and leaned down to press their lips together. He tasted like fresh coffee.

After a few seconds, he pulled away. "Well?" he asked, "Do you want to learn?"

Senku nodded breathlessly.

Gen smiled and kissed him again, longer this time. Senku kissed him back, and Gen felt a strong hand grip the front of his shirt as he pressed his warmth into his lips. "Please teach me," Senku mumbled against his mouth.

After a few seconds, Gen finally broke the kiss, smiling as he took Senku's hand a second time, prompting him to stand. "Come on, then," he teased. Gen's apartment was tiny, and it took them all of ten seconds to reach the bedroom. Senku was attacking Gen's lips with his own before the door was even closed behind them, gliding his tongue across his bottom lip as if asking for entrance, which was gladly permitted.

He could remember the very first time he and Gen had kissed like this. The sensation of another person's tongue against his own had been odd to him, and admittedly a little gross. Over time, though, he grew to crave such intimacy, wanting more than anything to experience Gen in every way possible. Maybe it was the scientist in him - it was the very basis of science to exploit every one of your senses when taking in new things. Sight, sound, smell, taste, and _touch_.

And oh, how wonderful Gen was to touch. How wonderful he was to be touched by. Senku felt it when even they simply held hands. It was arguably the most innocent form of contact, but the electricity it sent pulsing through Senku's veins was exhilarating, even after having known Gen for almost a year now.

Now, laying back on Gen's bed, his breathing trembled and his hands shook slightly as he undid his tie. He was about to have Gen all over him, on top of him, possibly _inside_ _of him_.

"Are you okay?" Gen asked, on his knees before him.

"Ten billion percent."

"Really?" Gen reached out and took Senku's trembling fingers in his own.

"...Okay, five billion percent," Senku said, a slight blush creeping up his cheeks.

"It's okay to be nervous, Senku-chan," Gen assured him, giving his hands a squeeze, "We won't do anything you're not comfortable with, and we can stop at any time. That's a promise."

Senku's heart was pounding as he gave a small smile. "I know. I trust you."

Gen released his hands, and his fingers travelled down to Senku's shirt, helping him unbutton it. When the last button was undone, Senku shrugged the article of clothing off, revealing his slender torso. The sun was setting outside, he was absolutely glowing in the last rays of golden light shining in through the window. Gen ran his fingers over his torso, reveling in how soft his skin was. Senku wasn't muscular; he didn't have toned abs or anything of the like. Senku's body was composed of a perfectly average skeleton, covered by an average amount of fat, and the minimum amount of muscle that allowed him to function - Gen wouldn't change any of it.

"You're beautiful," he murmured, "So beautiful, Senku-chan."

"You're just saying that," Senku replied, not making eye contact.

"I'm not. You're absolutely breathtaking. I love you." He kissed him, first on the lips, then moved on to his jawline, his neck, his chest.

"I love you," Senku said back, under his breath. It wasn't the first time they had said it, but it held all the same weight. Then he smirked, tugging playfully at Gen's t-shirt. "Hey, why am I the only one getting naked, here? Take it off, mentalist."

"Oops, my bad!" Gen said in his usual singsong tone. He giggled as he grabbed the edges of his shirt and pulled it up over his head. "Like what you see?"

Senku nodded. "So pretty," he mumbled, a blush painting his cheeks. He reached out to place his hands on Gen's waist, pausing just before making contact as if waiting for approval.

"What's with the hover hand? Go on, I don't bite," Gen urged with a little laugh. Senku rested his hands on the curve of his partner's waist nervously, cautiously. He then leaned in and, mimicking what Gen had done to him a moment ago, left a trail of soft kisses along his collarbone and up to his shoulder. When he reached the the crook of his neck he paused, nuzzling his nose against Gen's soft skin and inhaling deeply, taking in his sweet scent, the warmth his body gave off. "I love you so much," he mumbled against his skin.

Gen pressed a soft kiss into Senku's hair, stroking the back of his neck. "I love you, too, darling. Let me show you how much I love you."

He moved his free hand downward, to the front of Senku's pants. He worked the button loose as quickly as he could with a single hand, then tugged the zipper down as well. Senku gasped softly as Gen's knuckles brushed his semi-hard dick through the fabric of his boxer briefs, making it twitch from arousal. Gen hooked his thumb over the edge of the blonde's pants and tugged them down around his thighs, Senku shifting to allow them to slide off his butt. He then kicked them off the rest of the way, leaving him in only his underwear. Gen moved away to pull his own pants off, revealing the outline of his own stiffening cock through the fabric of his underwear. Senku marveled at the sight, this being the most of Gen he had ever laid eyes on.

"Put your hands on me, Gen," Senku spoke, almost in a whisper, "P-put your mouth on me. All over me."

"Oh yeah?" Gen smirked, "Like this?" He placed his hands on Senku's thighs, just above his knees, gently spreading his legs before leaning forward to kiss his inner thigh. This time his kisses were sloppy, leaving a wet trail as he moved upward, closer and closer to Senku's groin, making him squirm. "Ah!" he gasped as Gen playfully grabbed a bit of the fabric of his underwear with his teeth, tugging them down just enough to reveal a bit of the dark brown hair at the base of his dick. He was so on edge that the slight friction was enough to heighten his arousal even more. Letting go of his underwear, Gen moved upward to work his mouth over Senku's lower abdomen. He smiled at the feeling of Senku wiggling beneath him as he pressed a soft, playful kiss onto his belly button ("Stop it, that tickles!"), then moved on once again, leaving a wet stripe with his tongue from Senku's naval to his chest. Sweet little whimpers, the smallest sounds of pleasure, escaped Senku's throat here and there.

He began working his mouth on one of Senku's nipples, swirling his tongue around the little pink bud, and he was about to start rubbing the other one with his thumb when Senku suddenly tensed up. "Stop," he said, sounding slightly panicked. Gen quickly pulled away, looking up in concern, and Senku immediately crossed his arms over his chest to cover up where the older boy's mouth had just been. "Not there," he said quietly.

"A-are you okay? Did I hurt you?"

"No. I just don't like being touched there. I don't like how it feels."

"Ah," Gen sighed, relieved that he hadn't somehow hurt him, "Got it. No nipples, no problem." He gave a thumbs up, and Senku snickered at the cheesy line. Gen continued, "Do you want to keep going?"

"Yes," Senku nodded. Looking away shyly, he added, "Sorry for, uh, ruining the mood."

"You didn't," Gen reached to caress Senku's cheek, "We're just learning each other's bodies. That's part of it, dear Senku."

"Just trial and error?" Senku mumbled, more to himself than to his partner, "Like a science experiment, then."

Gen chuckled, kissing him on the lips. After a few seconds, he was surprised by Senku pulling away first, the boy's crazy hair tickling the side of his face as he shifted to attack his neck with kisses. "Ah!" Gen gasped as Senku nipped at the skin underneath his ear. The red marks he was leaving would surely become little bruises by morning. "Ah, that feels good."

With this approval from Gen, Senku worked his way down his neck, leaving little love bites as he went. Gen had refrained from using his teeth on Senku, opting to keep it nice and gentle for his first time, but Senku clearly had other ideas for him. As he kissed him, Senku reached down, hesitating for a second before grabbing Gen's cock, palming him through his boxers. Gen gasped at the sudden stimulation, and Senku felt the cock in his hand twitch. He hooked his thumb over the band of his underwear and pulled them down, Gen's erection springing up upon release. Senku paused, staring down at it in slight awe. He'd never seen someone like this, fully exposed, on display just for him. His heart raced as he wrapped his fingers around Gen's length, slowly pumping his hand up and down.

"Nn," Gen whimpered, "Ah, _fuck_ , Senku-chan."

"D-does that feel good?"

"Feels _so_ good," Gen mumbled into Senku's hair. Senku moved his hand a bit faster, rubbing Gen's tip with his thumb. He observed his partner's reactions closely, made note of every pleased little noise he made. He wanted to make him feel good, now and every single time they did this in the future.

"Take yours off," Gen urged, tugging lightly at the waistband of Senku's underwear. Senku shifted so he could slide them off, dropping them to the floor. His breath caught in his throat and his face heated up as he looked down at himself, his erection on full display. It shouldn't have flustered him so much; he was a scientist after all. The human body is nothing to get embarrassed about. But finding himself completely exposed to another person for the first time in his life, he couldn't seem to control the emotions flooding his brain. It was embarrassing, but it was also exhilarating, showing every bit of himself to Gen. In that moment, the person he loved was viewing _all_ of him, and it made his stomach swirl.

"Congratulations, Senku-chan! You've successfully completed the first part of my lesson plan: foreplay." Gen scooted closer to him, so close that their foreheads were touching and their breaths mingled. "Are you ready to go a step further, darling?"

"Yes," Senku replied without hesitation.

They kissed for about the hundredth time that night, deeply and passionately. "Do you want to be on top or bottom?" Gen asked, "I'm fine with either. Whatever you're most comfortable with."

Senku thought for a moment, before responding, "I want to feel you inside me."

" _Oh_ ," Gen breathed. It was a surprise, but it was a damn good one. He placed his hands on Senku's shoulders, gently pushing him backwards so he was laying down again, with Gen hovering over him. Gen opened the drawer of his bedside table, wrapping his fingers around the little bottle he kept hidden away securely. He pulled it out and waved it playfully in front of Senku's face. "Lesson one, part two! Shall I prep you? Or will you do it yourself?"

"You," Senku replied simply.

"Come 'ere, then," Gen said, sitting up. Senku bent his legs and scooted up a bit so his ass was in Gen's lap. Gen gently pushed his legs apart, watching the way his boyfriend's face flushed. This was only the preparation, and Senku couldn't believe the intimacy of it, being wide open like this in front of his lover.

Gen grinned mischievously as he squirted a generous amount of the clear gel onto his index finger. "Oh my, no need to be embarrassed, dear Senku," he said, "You're such a beautiful sight."

He pushed a bit of his finger into Senku's tight hole, and the younger boy gasped at the sudden sensation. Gen moved his finger around in a circular motion, opening him up. "Okay?" he asked his wide eyed boyfriend, who nodded. "I'm gonna go deeper, okay?" Senku nodded again, and Gen pressed further in.

"Ah!" Senku breathed. Gen moved his finger in and out, ever so slowly, letting Senku get used to the feeling. After a moment, he easily located his prostate, and he curled his finger, clawing at it through the skin. "Ah, ah fuck," Senku whimpered, "That feels good. _Fuck_ , it feels good."

"And that, dear Senku, is where the g-spot is. Any more questions?"

"Shut up."

"Can I add another finger?" Gen asked. Senku nodded eagerly, and the older boy complied, slipping in another digit. He moved a little faster now, scissoring his fingers to open him up.

"More," Senku pleaded.

"Yeah?" Gen smiled as he slipped a third finger into Senku's hole. He raked his fingers along Senku's walls repeatedly, paying special attention to that sweet, sensitive little spot. For the first time that night, Senku moaned out loud, not bothering to hold back.

"Do you feel like you're ready?" Gen asked after fingering him for a few more minutes.

"Yes," Senku replied, his eyes sparkling, "Gen, make love to me."

Gen felt like his heart would beat right out of his chest. _Gen, make love to me_.

Gen, make love to me.

Make love to me.

The words were so raw, so sensual, and coming from Senku...!

He coated his dick with another layer of lube, just to be safe, and, using his hand, positioned it so the tip just barely touched Senku's entrance. He leaned over Senku so they were face to face, their chests not quite touching, but close enough that they could feel the rise and fall of each breath the other took. Senku placed his hands on Gen's back, holding him close (as if Gen would ever pull away, even if he let go).

Gen eased his length in, taking in a sharp breath. "Fuck," he moaned, "fuck, Senku. _I'm inside you_. Ah, you feel so good."

"Gen," Senku breathed. His ruby eyes were glassy, forehead slick with sweat.

"You okay?" Gen asked, breathing heavily, lifting a hand to caress Senku's face.

"Yes," Senku replied, "It feels so good, Gen." He slid one of his hands to the back of Gen's head, pulling him in for a rough kiss.

Gen thrust his hips, once, twice, over and over until it became a steady rythym, accompanied only by their erratic moans and the creaking of the bed.

"You feel so good, baby," Gen rasped, "You're doing so good." Unlike Senku, this wasn't Gen's first time having sex, but it was his first time making love. There was a clear line between the two, Gen realized that now. In the past, he'd fucked and been fucked, but none of those times compared to what he was feeling now. Not just the pleasure, but the sheer intimacy of it. It was on another level. Sex was an entirely different experience when shared with someone you loved, and _god_ , he loved this man underneath him so fucking much.

Senku moaned ecstatically as their bodies rocked together. The head of his cock was red and swollen and leaking. "I don't feel- _Nn!_ -like I can last much longer," he gasped.

 _No one does their first time_ , was what Gen wanted to tell him, but he was already dangerously close to the edge himself. It was a little embarrassing - no, there was no need to feel embarrassed, not in front of Senku. "Neither can I," he replied, simply, "I'm so close."

They came together, hot and sticky, Gen pulling out just in time to shoot four, five, six times across Senku's chest. For a couple minutes, they were both silent, catching their breaths while coming down from the high of their orgasms. Senku laid there below Gen, covered in cum, trembling slightly from the intensity of it all. Gen kissed him, soft and sweet, mumbling against his lips, "You did so good, Senku. I love you so much."

Finally, he rolled over, laying next to his partner in bed. He grabbed his discarded t-shirt and helped Senku wipe off with it before tossing it carelessly to the floor.

"I've never felt anything like that before," Senku breathed.

Gen rolled over to face his lover, grasping his hand and lacing their fingers together. "Neither have I," he admitted, "and you were worried you wouldn't be good enough."

Senku's heart fluttered.

"Was I a good teacher?" Gen asked suddenly.

"What?"

"Did you forget already? I told you I would teach you! That was the whole point!"

Senku couldn't refrain from laughing. "Yeah, you were great. I think all my questions are answered." He rolled over to face Gen, blinking the sleepiness away from his eyes. Gen reached for the spare blanket he kept folded at the foot of the bed and covered them both from their waists down before snuggling up with his boyfriend, burying his face in his chest.

He was nearly asleep when he heard Senku, only half awake himself, mumble, "I'm looking forward to my next lesson."

**Author's Note:**

> writing smut has never been a strength of mine so i hope this wasn't a total disaster
> 
> if you enjoyed it pls validate my existence by leaving kudos and maybe a comment,, djdjsjjd thank you so much for reading !!


End file.
